Suggested Citation:
Restrepo, Laura and Lewis Fulton (2025)

Assessing Hydrogen Supply Chains: An Integrated Review of Leakage and Energy Efficiency Studies

. Institute of Transportation Studies, University of California, Davis, Journal Article UCD-ITS-RP-25-83

Abstract:

This article reviews and assesses studies that have estimated leakage rates and system efficiencies across the supply chain for liquid and gaseous hydrogen systems. Understanding both leakage and system efficiency (and their interactions) is crucial for optimizing hydrogen's role in the energy transition if it is to play an important role in global decarbonization. Through a detailed literature review, the paper compiles and evaluates existing estimates of leakage rates and efficiencies at various hydrogen supply chain stages, including production, storage, transmission, distribution, and end-use. The study develops average estimates across studies and combines estimates into scenarios to estimate system leakage rates and their impacts on system efficiencies; it also highlights knowledge gaps and areas for data improvement. A comparative analysis of liquid and gaseous hydrogen systems includes long-distance hydrogen transmission, urban distribution, and vehicle applications, offering insights into the most suitable systems for different scenarios. The results indicate that gaseous hydrogen systems generally outperform liquid systems in terms of efficiency and leakage minimization. However, liquid hydrogen has potential advantages in specific applications, particularly high-volume transportation, so strong incentives exist to lower its leakage rates. The study identifies critical areas for technological advancement, including improved liquefaction processes, enhanced insulation for liquid hydrogen storage and transport, and ongoing advances in hydrogen handling at liquid hydrogen stations. This paper offers guidance for policymakers, researchers, and industry stakeholders and can contribute to optimizing hydrogen systems and accelerating the transition to a sustainable, low-carbon energy future.